Abstract
We sought to define the relationship between cytokine stimulated release of matrix metalloproteinases (MMPs) and cell migration using adult rat cardiac fibroblasts. Interleukin-1beta (IL-1beta) increased release of MMP-2, -3, and -9, and TIMP-1, by 3-6-fold, measured by immunoblotting and gel zymography. Tumor necrosis factor-alpha (TNFalpha) augmented IL-1beta stimulated release of MMP-9, but not MMP-2 or -3. Transforming growth factor-beta1 (TGFbeta1) attenuated all the responses to IL-1beta. IL-1beta was also the most robust stimulus of adult rat cardiac fibroblast migration, measured in Boyden chamber assays. The combination of IL-1beta plus TNFalpha substantially enhanced migration, whereas TGFbeta1 strongly inhibited the migratory response to IL-1beta. The pan-selective MMP inhibitor GM 6001 effectively blocked IL-1beta stimulated migration. Pharmacologic inhibitors selective for ERK, JNK, and p38 MAP kinase pathways inhibited the IL-1beta regulation of individual MMPs. Increased MMP activity associated with migration of cardiac fibroblasts may be important determinants of cytokine-directed remodeling of injured myocardium.